1. Field of the Invention
The invention relates generally to a method for managing a group of dairy animals, comprising:                automatically milking a dairy animal, in the group of dairy animals, which presents itself at the milking station,        determining a subgroup of dairy animals to be separated from the group of dairy animals,        determining a separation period, defined by a start time and an end time, in which the dairy animals in the subgroup of dairy animals to be separated which present themselves at the milking station during the separation period are separated from the group of dairy animals.        
2. Description of the Related Art
In automatic milking systems, it is generally known to separate a subgroup of dairy animals which meet a predetermined criterion from a group of dairy animals in a milking shed area, for example to inseminate or give medical treatment to the dairy animals in the subgroup to be separated. In this case, the intention is that the dairy animals to be separated are separated from the other dairy animals in the group at a planned collection time into a separation area which is screened from the milking shed area.
In an automatic milking system, the dairy animals present themselves at a milking station which is provided with a milking robot. In order to separate the dairy animals in the subgroup, a predetermined separation period is set. The separation period is determined by the length of time from a start time, preceding the planned collection time, to the planned collection time. If the dairy animal has presented itself at the milking station outside of the separation period, it is guided back to the group of dairy animals, if appropriate following milking. If, however, the automatic milking occurs during the separation period, it is determined whether said dairy animal belongs in the subgroup to be separated. If that is the case, said dairy animal is subsequently separated. During the separation period, the dairy animals to be separated are therefore directed into the screened separation area, and the dairy animals which are not to be separated are guided back to the milking shed area.
In practice, however, it has been found that the predetermined separation period is not optimal for the dairy animals in the subgroup to be separated. If the separation period is relatively short, there is a risk that not all of the dairy animals to be separated will be collected in the separation area at the planned collection time. On the other hand, a relatively long separation period can lead to relatively long waiting times for the separated dairy animals in the separation area. As a result, the milking interval between two successive milking operations for those separated dairy animals can become so long that the milking behaviour and the milk production of said dairy animals are disrupted.